Crystalline poly aryl ketones resins are known in the art as polyaryl ether ketone (PAEK) resins. PAEK resins, for example polyaryl ketones, polyether ketones and polyether ether ketones, have very desirable properties, such as solvent resistance, flame resistance, low wear rate, abrasion resistance, and high strength.
However the relatively low glass transition temperatures (Tg) of these crystalline resins limits their use at high temperatures under load. This deficiency has been improved, but not solved, by the addition of fiber glass, carbon fibers and other reinforcements as well as mineral fillers. Unfortunately, these changes, while improving one property, adversely affect other properties. For example addition of fibers, increases weight, reduces flow and induces anisotropy in molded parts. Such anisotropy in a part may, for example, result in warp or other undesirable dimensional changes, such as curling in a film. In some instances the fiber additives can interfere with the surface smoothness of the shaped parts, causing uneven surface properties. This is especially true in thin parts and films. Addition of a reinforcing filler to PAEK resins will also make it difficult to extrude thin films and fibers.
Thus there exists a need for crystalline poly aryl ether ketone formulations with a range of improved properties, for instance load bearing capabilities at high temperature, while still having good melt processability allowing for their improved use in molded articles, sheets, films and fibers.